Composite structures are sometimes required to meet flammability performance specifications. Constituents of composite structures may vary in their flammability, consequently it may be necessary to consider the flammability of each of these constituents in designing a composite structure. For example, in the aircraft industry, certain types of joints are used to fabricate composite structures having radiused corners such as stow bins, closets, galleys and laboratories. These joints may require the use of adhesives in order to provide a joint that meets performance specifications for strength, durability and other requirements. Potting compounds are one form of adhesive that may be used to fill composite joints. Potting compounds may be desirable for filling joints because of their relatively low flammability, however in some applications, they may not provide the bond strength necessary to meet performance specifications. In other applications, high strength structural adhesives may be desirable for use in composite joints because of their relatively high bond strength, however such adhesives may exhibit less than desirable flammability when compared to lower strength potting compounds.
Accordingly, there is a need for flame retardant composite structures and a method of making the same that allow the use of high strength structural adhesives, particularly in areas of joints.